/* Native-dependent code for GNU/Linux i386.
- Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
- 2009, 2010, 2011 Free Software Foundation, Inc.
+ Copyright (C) 1999-2013 Free Software Foundation, Inc.
This file is part of GDB.
#include "regset.h"
#include "target.h"
#include "linux-nat.h"
+#include "linux-btrace.h"
+#include "btrace.h"
#include "gdb_assert.h"
-#include "gdb_string.h"
+#include <string.h>
#include "elf/common.h"
#include <sys/uio.h>
#include <sys/ptrace.h>
#include <sys/debugreg.h>
#endif
-#ifndef DR_FIRSTADDR
-#define DR_FIRSTADDR 0
-#endif
-
-#ifndef DR_LASTADDR
-#define DR_LASTADDR 3
-#endif
-
-#ifndef DR_STATUS
-#define DR_STATUS 6
-#endif
-
-#ifndef DR_CONTROL
-#define DR_CONTROL 7
-#endif
-
/* Prototypes for supply_gregset etc. */
#include "gregset.h"
#define PTRACE_SETREGSET 0x4205
#endif
+/* Per-thread arch-specific data we want to keep. */
+
+struct arch_lwp_info
+{
+ /* Non-zero if our copy differs from what's recorded in the thread. */
+ int debug_registers_changed;
+};
+
/* Does the current host support PTRACE_GETREGSET? */
static int have_ptrace_getregset = -1;
\f
}
/* GNU/Linux LWP ID's are process ID's. */
- tid = TIDGET (inferior_ptid);
+ tid = ptid_get_lwp (inferior_ptid);
if (tid == 0)
- tid = PIDGET (inferior_ptid); /* Not a threaded program. */
+ tid = ptid_get_pid (inferior_ptid); /* Not a threaded program. */
errno = 0;
val = ptrace (PTRACE_PEEKUSER, tid,
return;
/* GNU/Linux LWP ID's are process ID's. */
- tid = TIDGET (inferior_ptid);
+ tid = ptid_get_lwp (inferior_ptid);
if (tid == 0)
- tid = PIDGET (inferior_ptid); /* Not a threaded program. */
+ tid = ptid_get_pid (inferior_ptid); /* Not a threaded program. */
errno = 0;
regcache_raw_collect (regcache, regno, &val);
}
/* GNU/Linux LWP ID's are process ID's. */
- tid = TIDGET (inferior_ptid);
+ tid = ptid_get_lwp (inferior_ptid);
if (tid == 0)
- tid = PIDGET (inferior_ptid); /* Not a threaded program. */
+ tid = ptid_get_pid (inferior_ptid); /* Not a threaded program. */
/* Use the PTRACE_GETFPXREGS request whenever possible, since it
transfers more registers in one system call, and we'll cache the
}
/* GNU/Linux LWP ID's are process ID's. */
- tid = TIDGET (inferior_ptid);
+ tid = ptid_get_lwp (inferior_ptid);
if (tid == 0)
- tid = PIDGET (inferior_ptid); /* Not a threaded program. */
+ tid = ptid_get_pid (inferior_ptid); /* Not a threaded program. */
/* Use the PTRACE_SETFPXREGS requests whenever possible, since it
transfers more registers in one system call. But remember that
/* Support for debug registers. */
-static unsigned long i386_linux_dr[DR_CONTROL + 1];
-
/* Get debug register REGNUM value from only the one LWP of PTID. */
static unsigned long
int tid;
unsigned long value;
- tid = TIDGET (ptid);
+ tid = ptid_get_lwp (ptid);
if (tid == 0)
- tid = PIDGET (ptid);
+ tid = ptid_get_pid (ptid);
- /* FIXME: kettenis/2001-03-27: Calling perror_with_name if the
- ptrace call fails breaks debugging remote targets. The correct
- way to fix this is to add the hardware breakpoint and watchpoint
- stuff to the target vector. For now, just return zero if the
- ptrace call fails. */
errno = 0;
value = ptrace (PTRACE_PEEKUSER, tid,
offsetof (struct user, u_debugreg[regnum]), 0);
if (errno != 0)
-#if 0
perror_with_name (_("Couldn't read debug register"));
-#else
- return 0;
-#endif
return value;
}
{
int tid;
- tid = TIDGET (ptid);
+ tid = ptid_get_lwp (ptid);
if (tid == 0)
- tid = PIDGET (ptid);
+ tid = ptid_get_pid (ptid);
errno = 0;
ptrace (PTRACE_POKEUSER, tid,
perror_with_name (_("Couldn't write debug register"));
}
-/* Set DR_CONTROL to ADDR in all LWPs of LWP_LIST. */
+/* Return the inferior's debug register REGNUM. */
-static void
-i386_linux_dr_set_control (unsigned long control)
+static CORE_ADDR
+i386_linux_dr_get_addr (int regnum)
{
- struct lwp_info *lp;
- ptid_t ptid;
+ /* DR6 and DR7 are retrieved with some other way. */
+ gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
- i386_linux_dr[DR_CONTROL] = control;
- ALL_LWPS (lp, ptid)
- i386_linux_dr_set (ptid, DR_CONTROL, control);
+ return i386_linux_dr_get (inferior_ptid, regnum);
}
-/* Set address REGNUM (zero based) to ADDR in all LWPs of LWP_LIST. */
+/* Return the inferior's DR7 debug control register. */
-static void
-i386_linux_dr_set_addr (int regnum, CORE_ADDR addr)
+static unsigned long
+i386_linux_dr_get_control (void)
{
- struct lwp_info *lp;
- ptid_t ptid;
+ return i386_linux_dr_get (inferior_ptid, DR_CONTROL);
+}
- gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
+/* Get DR_STATUS from only the one LWP of INFERIOR_PTID. */
+
+static unsigned long
+i386_linux_dr_get_status (void)
+{
+ return i386_linux_dr_get (inferior_ptid, DR_STATUS);
+}
+
+/* Callback for iterate_over_lwps. Update the debug registers of
+ LWP. */
+
+static int
+update_debug_registers_callback (struct lwp_info *lwp, void *arg)
+{
+ if (lwp->arch_private == NULL)
+ lwp->arch_private = XCNEW (struct arch_lwp_info);
- i386_linux_dr[DR_FIRSTADDR + regnum] = addr;
- ALL_LWPS (lp, ptid)
- i386_linux_dr_set (ptid, DR_FIRSTADDR + regnum, addr);
+ /* The actual update is done later just before resuming the lwp, we
+ just mark that the registers need updating. */
+ lwp->arch_private->debug_registers_changed = 1;
+
+ /* If the lwp isn't stopped, force it to momentarily pause, so we
+ can update its debug registers. */
+ if (!lwp->stopped)
+ linux_stop_lwp (lwp);
+
+ /* Continue the iteration. */
+ return 0;
}
-/* Set address REGNUM (zero based) to zero in all LWPs of LWP_LIST. */
+/* Set DR_CONTROL to ADDR in all LWPs of the current inferior. */
static void
-i386_linux_dr_reset_addr (int regnum)
+i386_linux_dr_set_control (unsigned long control)
{
- i386_linux_dr_set_addr (regnum, 0);
+ ptid_t pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
+
+ iterate_over_lwps (pid_ptid, update_debug_registers_callback, NULL);
}
-/* Get DR_STATUS from only the one LWP of INFERIOR_PTID. */
+/* Set address REGNUM (zero based) to ADDR in all LWPs of the current
+ inferior. */
-static unsigned long
-i386_linux_dr_get_status (void)
+static void
+i386_linux_dr_set_addr (int regnum, CORE_ADDR addr)
{
- return i386_linux_dr_get (inferior_ptid, DR_STATUS);
+ ptid_t pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
+
+ gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
+
+ iterate_over_lwps (pid_ptid, update_debug_registers_callback, NULL);
}
-/* Unset MASK bits in DR_STATUS in all LWPs of LWP_LIST. */
+/* Called when resuming a thread.
+ If the debug regs have changed, update the thread's copies. */
static void
-i386_linux_dr_unset_status (unsigned long mask)
+i386_linux_prepare_to_resume (struct lwp_info *lwp)
{
- struct lwp_info *lp;
- ptid_t ptid;
+ int clear_status = 0;
- ALL_LWPS (lp, ptid)
+ /* NULL means this is the main thread still going through the shell,
+ or, no watchpoint has been set yet. In that case, there's
+ nothing to do. */
+ if (lwp->arch_private == NULL)
+ return;
+
+ if (lwp->arch_private->debug_registers_changed)
{
- unsigned long value;
-
- value = i386_linux_dr_get (ptid, DR_STATUS);
- value &= ~mask;
- i386_linux_dr_set (ptid, DR_STATUS, value);
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (lwp->ptid));
+ int i;
+
+ /* See amd64_linux_prepare_to_resume for Linux kernel note on
+ i386_linux_dr_set calls ordering. */
+
+ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
+ if (state->dr_ref_count[i] > 0)
+ {
+ i386_linux_dr_set (lwp->ptid, i, state->dr_mirror[i]);
+
+ /* If we're setting a watchpoint, any change the inferior
+ had done itself to the debug registers needs to be
+ discarded, otherwise, i386_stopped_data_address can get
+ confused. */
+ clear_status = 1;
+ }
+
+ i386_linux_dr_set (lwp->ptid, DR_CONTROL, state->dr_control_mirror);
+
+ lwp->arch_private->debug_registers_changed = 0;
}
+
+ if (clear_status || lwp->stopped_by_watchpoint)
+ i386_linux_dr_set (lwp->ptid, DR_STATUS, 0);
}
static void
-i386_linux_new_thread (ptid_t ptid)
+i386_linux_new_thread (struct lwp_info *lp)
{
- int i;
+ struct arch_lwp_info *info = XCNEW (struct arch_lwp_info);
- for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
- i386_linux_dr_set (ptid, i, i386_linux_dr[i]);
+ info->debug_registers_changed = 1;
- i386_linux_dr_set (ptid, DR_CONTROL, i386_linux_dr[DR_CONTROL]);
+ lp->arch_private = info;
}
+
+/* linux_nat_new_fork hook. */
+
+static void
+i386_linux_new_fork (struct lwp_info *parent, pid_t child_pid)
+{
+ pid_t parent_pid;
+ struct i386_debug_reg_state *parent_state;
+ struct i386_debug_reg_state *child_state;
+
+ /* NULL means no watchpoint has ever been set in the parent. In
+ that case, there's nothing to do. */
+ if (parent->arch_private == NULL)
+ return;
+
+ /* Linux kernel before 2.6.33 commit
+ 72f674d203cd230426437cdcf7dd6f681dad8b0d
+ will inherit hardware debug registers from parent
+ on fork/vfork/clone. Newer Linux kernels create such tasks with
+ zeroed debug registers.
+
+ GDB core assumes the child inherits the watchpoints/hw
+ breakpoints of the parent, and will remove them all from the
+ forked off process. Copy the debug registers mirrors into the
+ new process so that all breakpoints and watchpoints can be
+ removed together. The debug registers mirror will become zeroed
+ in the end before detaching the forked off process, thus making
+ this compatible with older Linux kernels too. */
+
+ parent_pid = ptid_get_pid (parent->ptid);
+ parent_state = i386_debug_reg_state (parent_pid);
+ child_state = i386_debug_reg_state (child_pid);
+ *child_state = *parent_state;
+}
+
\f
/* Called by libthread_db. Returns a pointer to the thread local
call.
Is this function needed? I'm guessing that the `base' is the
- address of a a descriptor that libthread_db uses to find the
+ address of a descriptor that libthread_db uses to find the
thread local address base that GDB needs. Perhaps that
descriptor is defined by the ABI. Anyway, given that
libthread_db calls this function without prompting (gdb
static void
i386_linux_resume (struct target_ops *ops,
- ptid_t ptid, int step, enum target_signal signal)
+ ptid_t ptid, int step, enum gdb_signal signal)
{
- int pid = PIDGET (ptid);
+ int pid = ptid_get_pid (ptid);
int request;
regcache_cooked_read_unsigned (regcache, I386_ESP_REGNUM, &sp);
if (syscall == SYS_rt_sigreturn)
- addr = read_memory_integer (sp + 8, 4, byte_order) + 20;
+ addr = read_memory_unsigned_integer (sp + 8, 4, byte_order)
+ + 20;
else
addr = sp;
}
}
- if (ptrace (request, pid, 0, target_signal_to_host (signal)) == -1)
+ if (ptrace (request, pid, 0, gdb_signal_to_host (signal)) == -1)
perror_with_name (("ptrace"));
}
static uint64_t xcr0;
/* GNU/Linux LWP ID's are process ID's. */
- tid = TIDGET (inferior_ptid);
+ tid = ptid_get_lwp (inferior_ptid);
if (tid == 0)
- tid = PIDGET (inferior_ptid); /* Not a threaded program. */
+ tid = ptid_get_pid (inferior_ptid); /* Not a threaded program. */
#ifdef HAVE_PTRACE_GETFPXREGS
if (have_ptrace_getfpxregs == -1)
return tdesc_i386_linux;
}
+/* Enable branch tracing. */
+
+static struct btrace_target_info *
+i386_linux_enable_btrace (ptid_t ptid)
+{
+ struct btrace_target_info *tinfo;
+ struct gdbarch *gdbarch;
+
+ errno = 0;
+ tinfo = linux_enable_btrace (ptid);
+
+ if (tinfo == NULL)
+ error (_("Could not enable branch tracing for %s: %s."),
+ target_pid_to_str (ptid), safe_strerror (errno));
+
+ /* Fill in the size of a pointer in bits. */
+ gdbarch = target_thread_architecture (ptid);
+ tinfo->ptr_bits = gdbarch_ptr_bit (gdbarch);
+
+ return tinfo;
+}
+
+/* Disable branch tracing. */
+
+static void
+i386_linux_disable_btrace (struct btrace_target_info *tinfo)
+{
+ int errcode = linux_disable_btrace (tinfo);
+
+ if (errcode != 0)
+ error (_("Could not disable branch tracing: %s."), safe_strerror (errcode));
+}
+
+/* Teardown branch tracing. */
+
+static void
+i386_linux_teardown_btrace (struct btrace_target_info *tinfo)
+{
+ /* Ignore errors. */
+ linux_disable_btrace (tinfo);
+}
+
+/* -Wmissing-prototypes */
+extern initialize_file_ftype _initialize_i386_linux_nat;
+
void
_initialize_i386_linux_nat (void)
{
i386_dr_low.set_control = i386_linux_dr_set_control;
i386_dr_low.set_addr = i386_linux_dr_set_addr;
- i386_dr_low.reset_addr = i386_linux_dr_reset_addr;
+ i386_dr_low.get_addr = i386_linux_dr_get_addr;
i386_dr_low.get_status = i386_linux_dr_get_status;
- i386_dr_low.unset_status = i386_linux_dr_unset_status;
+ i386_dr_low.get_control = i386_linux_dr_get_control;
i386_set_debug_register_length (4);
/* Override the default ptrace resume method. */
t->to_read_description = i386_linux_read_description;
+ /* Add btrace methods. */
+ t->to_supports_btrace = linux_supports_btrace;
+ t->to_enable_btrace = i386_linux_enable_btrace;
+ t->to_disable_btrace = i386_linux_disable_btrace;
+ t->to_teardown_btrace = i386_linux_teardown_btrace;
+ t->to_read_btrace = linux_read_btrace;
+
/* Register the target. */
linux_nat_add_target (t);
linux_nat_set_new_thread (t, i386_linux_new_thread);
+ linux_nat_set_new_fork (t, i386_linux_new_fork);
+ linux_nat_set_forget_process (t, i386_forget_process);
+ linux_nat_set_prepare_to_resume (t, i386_linux_prepare_to_resume);
}
projects / deliverable / binutils-gdb.git / blobdiff